Magnetic recording tape backside having both low friction and low surface roughness

Abstract

A magnetic recording tape includes an elongated substrate, a magnetic coating disposed on a first side of the substrate, and a backside coated on a second side of the substrate. The magnetic coating includes an exposed magnetic recording layer and a support layer deposited on the substrate between the substrate and the exposed magnetic recording layer. The backside is coated on the substrate opposite the first side and has a roughness average Ra of less than about 18 nm and a friction force of less than about 70 g-force.

1 . A magnetic recording tape comprising:
 an elongated substrate;   at least one magnetic coating disposed on a first side of the substrate and including:
 an exposed magnetic recording layer, 
 at least one support layer deposited on the substrate between the substrate and the exposed magnetic recording layer; and 
   a backside coated on a second side of the substrate opposite the first side;   wherein the backside has a roughness average Ra of less than about 18 nm and a friction force of less than about 70 g-force.   
   
   
       2 . The magnetic recording tape of  claim 1 , wherein the friction force comprises a 5-pass static friction force that is less than about 70 g-force. 
   
   
       3 . The magnetic recording tape of  claim 1 , wherein the friction force comprises a 5-pass dynamic friction force that is less than about 70 g-force. 
   
   
       4 . The magnetic recording tape of  claim 1 , wherein the backside roughness average Ra is less than about 15 nm and the friction force comprises an 8-pass max friction force that is less than about 70 g-force. 
   
   
       5 . The magnetic recording tape of  claim 1 , wherein the backside roughness average Ra is between about 5-15 nm and the friction force comprises an 8-pass max friction force that is less than about 70 g-force. 
   
   
       6 . The magnetic recording tape of  claim 1 , wherein the backside roughness average Ra is between about 5-15 nm and the friction force comprises a 5-pass static friction force is less than about 70 g-force. 
   
   
       7 . The magnetic recording tape of  claim 1 , wherein the backside roughness average Ra is between about 5-15 nm and the friction force comprises a 5-pass dynamic friction force is less than about 60 g-force. 
   
   
       8 . The magnetic recording tape of  claim 1 , wherein the friction force comprises an average friction force that is an average of 8 friction force values, and further wherein the 8 friction force values are substantially equal. 
   
   
       9 . The magnetic recording tape of  claim 8 , wherein a last friction force value is different from a first friction force value by less than about 50%. 
   
   
       10 . The magnetic recording tape of  claim 8 , wherein a last friction force value is different from a first friction force value by less than about 20%. 
   
   
       11 . The magnetic recording tape of  claim 1 , wherein the backside is characterized by an absence of load bearing particles. 
   
   
       12 . A magnetic recording tape comprising:
 an elongated substrate;   a magnetic front side coated on a first side of the substrate; and   a backside coated on a second side of the substrate opposite the magnetic front side;   wherein the backside has a roughness average Ra of less than about 18 nm and a 5-pass friction force of less than about 70 g-force.   
   
   
       13 . The magnetic recording tape of  claim 12 , wherein the backside is characterized by an absence of load bearing particles. 
   
   
       14 . The magnetic recording tape of  claim 12 , wherein the backside has a root mean square roughness Rq of less than about 20 nm. 
   
   
       15 . The magnetic recording tape of  claim 12 , wherein the backside has a roughness depth Rz of less than about 170 nm. 
   
   
       16 . The magnetic recording tape of  claim 12 , wherein the backside has a roughness average Ra of less than about 18 nm and further comprises a friction characterized by a non-increasing set of 8 static friction force values. 
   
   
       17 . The magnetic recording tape of  claim 12 , wherein the backside has a roughness average Ra of less than about 18 nm and further comprises a friction characterized by a non-increasing set of 8 dynamic friction force values. 
   
   
       18 . A method of fabricating a magnetic recording tape comprising:
 providing a substrate;   coating a magnetic layer onto a first side of the substrate;   coating a backside onto the substrate opposite the magnetic layer;   configuring the backside to have a roughness average Ra of less than about 18 nm; and   simultaneously configuring the backside to have a 5-pass friction force of less than about 70 g-force.   
   
   
       19 . The method of  claim 18 , further comprising:
 configuring the backside to have a root mean square roughness Rq of less than about 20 nm.   
   
   
       20 . The method of  claim 18 , further comprising:
 configuring the backside to have a roughness depth Rz of less than about 170 nm.   
   
   
       21 . The method of  claim 18 , further comprising:
 configuring the backside to have a non-increasing set of 8 dynamic friction force values and 8 static friction force values.   
   
   
       22 . The method of  claim 18 , wherein coating a backside onto the substrate opposite the magnetic layer comprises coating a backside having an absence of load bearing particles onto the substrate opposite the magnetic layer. 
   
   
       23 . A magnetic recording tape comprising:
 an elongated substrate;   a magnetic front side coated on a first side of the substrate; and   a backside coated on a second side of the substrate opposite the magnetic front side;   wherein the backside is characterized by an absence of load bearing particles, has a roughness average Ra of less than about 10 nm, a 5-pass static friction force of less than about 70 g-force, and a 5-pass dynamic friction force of less than about 70 g-force.